Bad Polishing Results

[kenykirschstein]

I built an aluminum frame from 1.5 inch square .125 tubing. The tubing didn't look that good so I thought I would try polishing. Went down HarborFreight bought a 4" spiral sewn buffing pad and some red compound. I put this on a 12,000 rpm grinder and went to town. Didn't pay attention to cutting or polishing and typically went perpendicular to the tubing. I was amazed at the results, I polished it so bright it looked like deep rich chrome. I then thought how much better if I did a professional job. So I researched and found this web site, looked at all the stuff I needed and then bought $150 worth of stuff. (Lot more expense then my $4 test case). I sanded the frame, 100, 150, 220, 320, 500, scotch brite. Ready to polish. Used a polisher, 3000 rpm with 8" wheel. Used the black compound and sisal wheel, followed by red and spiral wheel. The results wasn't what I expected. The metal polished but there seemed to be areas of cloudiness in the metal, areas of black residue in the metal. I tried more heat from the pad and some of the black disappeared but the metal still looked like it had a cloudy haze down inside the metal. The metal is polishing to a shiny luster, just cloudy. It doesn't look as good as my intial testing case with cheap supplies and no prep. I did not use the white compound with cotton wheel because I didn't think it would do any good and might mess up the wheel with residue. I'm sure it has to be an operator error. Any Advice? I know with the supplies and equipment I have I should get a deep clear shine.... at least I think so.

[tomg552001]

I suggest reading the buff manual. It basically layouts the proper way to polish. The most important thing in my mind is to do 75 percent of the work with the sisal wheel and black emory before moving into brown. Also, MAKE SURE you use the white. The white colors the part really well and helps remove haze and give it a chrome like shine. You should be using sisal with black, brown with spiral sewn, and white with a loose or canton flannel. Also, inbetween compounds make sure to clean the apart to remove excess compounds. Read the buff manual, give polishing another shot than report back and we'll see what else we can help you with.

[kenykirschstein]

I did read the manual and have the general concept.
What is the best way to apply the compound when you are using a hand buffer. The manual says to put it on before the piece, if you have a frame the only way you can do that is to run the pad perpendicular to the piece which isn't what I think you want to do. Also it seems a little unsafe to run the buffer, hold the compound and try to apply the compound. Am I missing something here? The one thing I didn't do was clean the metal between the black and red compound. Both buffing pads turned gray pretty fast from the metal residue. What is best way to clean between buffing compounds. Like I stated the issue really isn't the polish but the haze and black grit in the pores of the metal. The manual hasn't stated anything different than what I already did except for what I stated. I'm sure this is a common problem and must be attributed to something obvious.

[tomg552001]

If you have pits in the metal where the black spots are getting stored chances are you need to sand more. scotch brite is not needed, just wet sand to a 400 thouroughly and pick up some greaseless compounds. Also, try using the white, it will help with the haze and use a brake cleaner etc inbetween compounds. Most importantly, make sure to use the proper polishing motions, with to color, against the wheel to cut. What type of metal are you trying to polish? Got any pics? Pics help a lot in troubleshooting whats going wrong.

[red1966malibu]

This is a technique I use for aluminum that works very well.
If part has deep scratches use 220 grit sand paper, finish with 400 grit.
Buff with tripoli on sisal wheel, follow with tripoli on vented buff,
and finish with loose wheel and white rogue. This should give
a mirror finish without leaving scratches.